Magnetic memory device

ABSTRACT

A magnetic memory device includes a reference magnetic structure, a free magnetic structure, and a tunnel barrier pattern between the reference magnetic structure and the free magnetic structure. The reference magnetic structure includes a first pinned pattern, a second pinned pattern between the first pinned pattern and the tunnel barrier pattern, and an exchange coupling pattern between the first and the second pinned pattern. The second pinned pattern includes a first magnetic pattern adjacent the exchange coupling pattern, a second magnetic pattern adjacent the tunnel barrier pattern, a third magnetic pattern between the first and the second magnetic pattern, a first non-magnetic pattern between the first and the third magnetic pattern, and a second non-magnetic pattern between the second and the third magnetic pattern. The first non-magnetic pattern has a different crystal structure from the second non-magnetic pattern, and at least a portion of the third magnetic pattern is amorphous.

REFERENCE TO PRIORITY APPLICATION

This U.S. non-provisional patent application is a continuationapplication of and claims priority from U.S. patent application Ser. No.15/617,012, filed on Jun. 8, 2017, which claims priority under 35 U.S.C.§ 119 to Korean Patent Application No. 10-2016-0143509, filed on Oct.31, 2016, the entire content of each of the above applications isincorporated by reference herein.

BACKGROUND

Embodiments of the inventive concepts relate to semiconductor memorydevices, and more particularly, to a magnetic memory devices.

Due to increasing demand for electronic devices with a high speed and/orlow power consumption, semiconductor devices may require fasteroperating speeds and/or lower operating voltages. Magnetic memorydevices have been suggested to satisfy such requirements. For example,magnetic memory devices can provide technical advantages, such asreduced latency and/or non-volatility. As a result, magnetic memorydevices may be used in next-generation memory devices.

Generally, a magnetic memory device may include a magnetic tunneljunction pattern (MTJ). A magnetic tunnel junction pattern may includetwo magnetic layers and an insulating layer interposed the two magneticlayers. A resistance value of the magnetic tunnel junction pattern mayvary depending on magnetization directions of the two magnetic layers.For example, the resistance value of the magnetic tunnel junctionpattern may be higher when magnetization directions of the two magneticlayers are anti-parallel to each other than when they are parallel toeach other. Data can be stored into and/or read out from the magnetictunnel junction pattern by using a difference between these resistancevalues.

SUMMARY

According to some embodiments of the inventive concepts, a magneticmemory device may include a reference magnetic structure and a freemagnetic structure on a substrate, and a tunnel barrier pattern betweenthe reference magnetic structure and the free magnetic structure. Thereference magnetic structure includes a first pinned pattern, a secondpinned pattern between the first pinned pattern and the tunnel barrierpattern, and an exchange coupling pattern between the first pinnedpattern and the second pinned pattern. The second pinned patternincludes a first magnetic pattern adjacent the exchange couplingpattern, a second magnetic pattern adjacent the tunnel barrier pattern,a third magnetic pattern between the first magnetic pattern and thesecond magnetic pattern, a first non-magnetic pattern between the firstmagnetic pattern and the third magnetic pattern, and a secondnon-magnetic pattern between the second magnetic pattern and the thirdmagnetic pattern. The first non-magnetic pattern has a different crystalstructure from the second non-magnetic pattern, and at least a portionof the third magnetic pattern is amorphous.

According to some embodiments of the inventive concepts, a magneticmemory device may include a reference magnetic structure and a freemagnetic structure on a substrate, and a tunnel barrier pattern betweenthe reference magnetic structure and the free magnetic structure. Thereference magnetic structure includes a first pinned pattern, a secondpinned pattern between the first pinned pattern and the tunnel barrierpattern, and an exchange coupling pattern between the first pinnedpattern and the second pinned pattern. The second pinned patternincludes a first magnetic pattern adjacent the exchange couplingpattern, a second magnetic pattern adjacent the tunnel barrier pattern,a third magnetic pattern between the first magnetic pattern and thesecond magnetic pattern, a first non-magnetic pattern between the firstmagnetic pattern and the third magnetic pattern, and a secondnon-magnetic pattern between the second magnetic pattern and the thirdmagnetic pattern. The first non-magnetic pattern includes a differentmaterial from the second non-magnetic pattern, and at least a portion ofthe third magnetic pattern is amorphous.

According to some embodiments of the inventive concepts, a magneticmemory device may include a magnetic tunnel junction (MTJ) pattern thatmay include a reference magnetic structure, a free magnetic structure,and a tunnel barrier pattern therebetween. The reference magneticstructure may include first and second pinned patterns and an exchangecoupling pattern therebetween. The second pinned pattern may include afirst magnetic pattern, a first non-magnetic pattern, a secondnon-magnetic pattern, and a second magnetic pattern that aresequentially stacked between the exchange coupling pattern and thetunnel barrier pattern. The first non-magnetic pattern and the firstmagnetic pattern may include a same crystal structure. The secondnon-magnetic pattern may include a different crystal structure than thefirst non-magnetic pattern. The second pinned pattern may furtherinclude a third magnetic pattern, which may be at least partiallyamorphous, between the first and second non-magnetic patterns.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be more clearly understood from the following briefdescription taken in conjunction with the accompanying drawings. Theaccompanying drawings represent non-limiting embodiments as describedherein.

FIG. 1 is a circuit diagram illustrating a memory cell array of amagnetic memory device according to embodiments of the inventiveconcepts.

FIG. 2 is a circuit diagram illustrating a unit memory cell of amagnetic memory device according to embodiments of the inventiveconcepts.

FIG. 3 is a cross-sectional view illustrating a magnetic memory deviceaccording to some embodiments of the inventive concepts.

FIG. 4 is an enlarged view illustrating a reference magnetic structure(RMS) of FIG. 3 according to some embodiments.

FIG. 5A is a diagram illustrating an arrangement of atoms in a firstmagnetic pattern and a first non-magnetic pattern of FIG. 3 when viewedin a plan view according to some embodiments.

FIG. 5B is a diagram illustrating an arrangement of atoms in a secondmagnetic pattern and a second non-magnetic pattern of FIG. 3 when viewedin a plan view according to some embodiments.

FIGS. 6 and 7 are cross-sectional views illustrating a method forfabricating a magnetic memory device according to some embodiments ofthe inventive concepts.

FIG. 8 is a cross-sectional view illustrating a magnetic memory deviceaccording to some embodiments of the inventive concepts.

FIGS. 9 to 11 are cross-sectional views illustrating a method forfabricating a magnetic memory device according to some embodiments ofthe inventive concepts.

It should be noted that these figures are intended to illustrate thegeneral characteristics of methods, structure and/or materials utilizedin certain example embodiments and to supplement the written descriptionprovided below. These drawings are not, however, to scale and may notprecisely reflect the precise structural or performance characteristicsof any given embodiment, and should not be interpreted as defining orlimiting the range of values or properties encompassed by exampleembodiments. For example, the relative thicknesses and positioning ofmolecules, layers, regions and/or structural elements may be reduced orexaggerated for clarity. The use of similar or identical referencenumbers in the various drawings is intended to indicate the presence ofa similar or identical element or feature.

DETAILED DESCRIPTION

Embodiments of the inventive concepts will now be described more fullywith reference to the accompanying drawings, in which embodiments areshown. Embodiments of the inventive concepts may, however, be embodiedin many different forms and should not be construed as being limited tothe embodiments set forth herein; rather, these embodiments are providedso that this disclosure will be thorough and complete, and will fullyconvey the concepts of embodiments to those of ordinary skill in theart.

FIG. 1 is a circuit diagram illustrating a memory cell array of amagnetic memory device according to embodiments of the inventiveconcepts. FIG. 2 is a circuit diagram illustrating a unit memory cell ofa magnetic memory device according to embodiments of the inventiveconcepts.

Referring to FIG. 1, the memory cell array 10 may include a plurality ofword lines WL0-WL3, a plurality of bit lines BL0-BL3 and unit memorycells MC. The unit memory cells MC may be two or three dimensionallyarranged. The word lines WL0-WL3 and the bit lines BL0-BL3 may beprovided to cross each other, and each of the unit memory cells MC maybe provided at a corresponding one of intersections between the wordlines WL0-WL3 and bit lines BL0-BL3. Each of the word lines WL0-WL3 maybe connected to a plurality of the unit memory cells MC. The unit memorycells MC connected to each of the word lines WL0-WL3 may be connected tothe bit lines BL0-BL3, respectively. The unit memory cells MC connectedto each of the bit lines BL0-BL3 may be connected to the word linesWL0-WL3, respectively. Accordingly, the unit memory cells MC connectedto the word line WL may be connected to a read and write circuit throughthe bit lines BL0-BL3, respectively.

Referring to FIG. 2, the unit memory cell MC may include a memoryelement ME and a select element SE. The memory element ME may beprovided between the bit line BL and the select element SE. The selectelement SE may be provided between the memory element ME and the wordline WL. The memory element ME may be a variable resistance device whoseresistance can be switched to one of at least two states by an electricpulse applied thereto.

The memory element ME may be formed to have a layered structure, whoseelectric resistance can be changed by a spin transfer process using anelectric current passing therethrough. For example, the memory elementME may have a layered structure configured to exhibit amagnetoresistance property, and may include at least one ferromagneticmaterial and/or at least one antiferromagnetic material.

The select element SE may be configured to selectively control a flow ofelectric charges passing through the memory element MC. For example, theselect element SE may be one of a diode, a p-n-p bipolar transistor, ann-p-n bipolar transistor, an n-channel metal-oxide-semiconductor fieldeffect transistor (NMOSFET) and a p-channel metal-oxide-semiconductorfield effect transistor (PMOSFET). When the select element SE is athree-terminal switching device, such as a bipolar transistor or aMOSFET, an additional interconnection line may be connected to theselect element SE.

The memory element ME may include a first magnetic structure MS1, asecond magnetic structure MS2 and a tunnel barrier TBR interposedtherebetween. The first magnetic structure MS1, the second magneticstructure MS2 and the tunnel barrier TBR may constitute or define amagnetic tunnel junction MTJ. The first and second magnetic structuresMS1 and MS2 may respectively include at least one magnetic layer formedof a magnetic material. The memory element ME may further include abottom electrode BE and a top electrode TE. The bottom electrode BE maybe interposed between the first magnetic structure MS1 and the selectelement SE, and the top electrode TE may be interposed between thesecond magnetic structure MS2 and the bit line BL.

FIG. 3 is a cross-sectional view illustrating a magnetic memory deviceaccording to some embodiments of the inventive concepts. FIG. 4 is anenlarged view illustrating a reference magnetic structure of FIG. 3.FIG. 5A is a diagram illustrating an arrangement of atoms in a firstmagnetic pattern and a first non-magnetic pattern of FIG. 3 when viewedin a plan view. FIG. 5B is a diagram illustrating an arrangement ofatoms in a second magnetic pattern and a second non-magnetic pattern ofFIG. 3 when viewed in a plan view.

Referring to FIG. 3, a lower interlayer insulating layer 102 may beprovided on a substrate 100. The substrate 100 may be a semiconductorsubstrate including silicon (Si), silicon-on-insulator (SOI), silicongermanium (SiGe), germanium (Ge), or gallium arsenide (GaAs). Selectionelements such, for example, field effect transistors or diodes may beprovided on the substrate 100, and the lower interlayer insulating layer102 may be provided to extend on or cover the selection elements. Thelower interlayer insulating layer 102 may include oxide, nitride and/oroxynitride.

A lower contact plug 104 may be provided in the lower interlayerinsulating layer 102. The lower contact plug 104 may penetrate the lowerinterlayer insulating layer 102 and may be electrically coupled to aterminal of a corresponding one of the selection elements. The lowercontact plug 104 may include at least one of doped semiconductormaterials (e.g., doped silicon), metals (e.g., tungsten, titanium and/ortantalum), conductive metal nitrides (e.g., titanium nitride, tantalumnitride and/or tungsten nitride) or metal-semiconductor compounds (e.g.,metal silicide).

A bottom electrode BE may be provided on the lower interlayer insulatinglayer 102. The bottom electrode BE may be electrically coupled to thelower contact plug 104. The bottom electrode BE may include a conductivematerial. As an example, the bottom electrode BE may include conductivemetal nitrides, such as titanium nitride and/or tantalum nitride.

A reference magnetic structure RMS and a free magnetic structure FMS maybe stacked on the lower interlayer insulating layer 102. A tunnelbarrier pattern TBR may be provided between the reference magneticstructure RMS and the free magnetic structure FMS. In some embodiments,the reference magnetic structure RMS may be provided between the bottomelectrode BE and the tunnel barrier pattern TBR.

The reference magnetic structure RMS may include at least one fixedlayer having a fixed magnetization direction, and the free magneticstructure FMS may include at least one free layer having a switchablemagnetization direction. The reference magnetic structure RMS, the freemagnetic structure FMS and the tunnel barrier pattern TBR may constituteor define a magnetic tunnel junction pattern MTJ. The magnetizationdirections of the fixed layer and the free layer may be substantiallyperpendicular to an interface between the tunnel barrier pattern TBR andthe free magnetic structure FMS. That is, the magnetic tunnel junctionpattern MTJ may be a perpendicular magnetization-type magnetic tunneljunction pattern.

A top electrode TE may be provided on the magnetic tunnel junctionpattern MTJ. The magnetic tunnel junction pattern MTJ may be interposedbetween the bottom electrode BE and the top electrode TE. In someembodiments, the free magnetic structure FMS may be provided between thetunnel barrier pattern TBR and the top electrode TE. The bottomelectrode BE, the magnetic tunnel junction pattern MTJ and the topelectrode TE may be provided to have vertically-aligned sidewalls. Thetop electrode TE may include a conductive material. As an example, thetop electrode TE may include at least one of tantalum (Ta), aluminum(Al), copper (Cu), gold (Au), silver (Ag), or titanium (Ti).

The reference magnetic structure RMS may include a syntheticantiferromagnetic (SAF) structure. As an example, the reference magneticstructure RMS may include a first pinned pattern 110, a second pinnedpattern 130 and an exchange coupling pattern 120 interposed between thefirst pinned pattern 110 and the second pinned pattern 130. The secondpinned pattern 130 may be provided between the first pinned pattern 110and the tunnel barrier pattern TBR. The exchange coupling pattern 120may couple the first pinned pattern 110 to the second pinned pattern 130in such a way that a magnetization direction 110 m of the first pinnedpattern 110 is anti-parallel to a magnetization direction 130 m of thesecond pinned pattern 130. Thus, magnetic fields generated by the firstand second pinned patterns 110 and 130 may offset each other to reduceor minimize a net magnetic field of the reference magnetic structureRMS. As a result, an influence of the magnetic field of the referencemagnetic structure RMS on the free magnetic structure FMS can be reducedor minimized. For example, the exchange coupling pattern 120 may includeruthenium (Ru).

The first pinned pattern 110 may include perpendicular magneticmaterials (e.g., CoFeTb, CoFeGd, CoFeDy), perpendicular magneticmaterials with L10 structure, CoPt-based materials withhexagonal-close-packed lattices and/or perpendicular magneticstructures. The L10 perpendicular magnetic material may include at leastone of L10 FePt, L10 FePd, L10 CoPd, or L10 CoPt. The perpendicularmagnetic structure may include magnetic layers and non-magnetic layersthat are alternatively and repeatedly stacked. For example, theperpendicular magnetic structure may include at least one of (Co/Pt)n,(CoFe/Pt)n, (CoFe/Pd)n, (Co/Pd)n, (Co/Ni)n, (CoNi/Pt)n, (CoCr/Pt)n or(CoCr/Pd)n, where n is the number of stacked pairs of the layers.

Referring to FIGS. 3 and 4, the second pinned pattern 130 may include afirst magnetic pattern 140, a second magnetic pattern 142, a thirdmagnetic pattern 144, a first non-magnetic pattern 150 and a secondnon-magnetic pattern 152. The first magnetic pattern 140 may be adjacentthe exchange coupling pattern 120. The second magnetic pattern 142 maybe adjacent the tunnel barrier pattern TBR. The third magnetic pattern144 may be provided between the first magnetic pattern 140 and thesecond magnetic pattern 142. The first non-magnetic pattern 150 may beprovided between the first magnetic pattern 140 and the third magneticpattern 144. The second non-magnetic pattern 152 may be provided betweenthe second magnetic pattern 142 and the third magnetic pattern 144.

The first magnetic pattern 140 may be in contact with the exchangecoupling pattern 120. The first magnetic pattern 140 may beanti-ferromagnetically coupled to the first pinned pattern 110 throughthe exchange coupling pattern 120. The exchange coupling pattern 120 maycouple the first pinned pattern 110 to the first magnetic pattern 140 insuch a way that the magnetization direction 110 m of the first pinnedpattern 110 is anti-parallel to a magnetization direction 140 m of thefirst magnetic pattern 140. That is, the magnetization direction 140 mof the first magnetic pattern 140 may be anti-parallel to themagnetization direction 110 m of the first pinned pattern 110.

The first magnetic pattern 140 may have a hexagonal close-packed (HCP)crystal structure or a face centered cubic (FCC) crystal structure. Whenthe first magnetic pattern 140 has the hexagonal close-packed (HCP)crystal structure, the first magnetic pattern 140 may be provided tohave a (0001) plane parallel to the interface between the tunnel barrierpattern TBR and the free magnetic structure FMS. When the first magneticpattern 140 has the face centered cubic (FCC) crystal structure, thefirst magnetic pattern 140 may be provided to have a (111) planeparallel to the interface between the tunnel barrier pattern TBR and thefree magnetic structure FMS. In some embodiments, the interface betweenthe tunnel barrier pattern TBR and the free magnetic structure FMS maybe substantially parallel to a top surface of the substrate 100. Thus, a(0001) plane of the first magnetic pattern 140 having a hexagonalclose-packed (HCP) crystal structure, or a (111) plane of the firstmagnetic pattern 140 having a face centered cubic (FCC) crystalstructure may be substantially parallel to the top surface of thesubstrate 100.

Referring to FIG. 5A, when viewed in a plan view (e.g., when viewed in aplan view parallel to the top surface of the substrate 100), atoms inthe first magnetic pattern 140 may be arranged to have a 6-foldsymmetry. A line L1 shown in FIG. 5A is a virtual line representing acrystal plane lattice, a line S1 is a virtual line representing anatomic arrangement of the 6-fold symmetry. The first magnetic pattern140 may include a magnetic material that enhances antiferromagneticcoupling with the first pinned pattern 110. For example, the firstmagnetic pattern 140 may include at least one of cobalt (Co) or nickel(Ni).

The first non-magnetic pattern 150 may have a hexagonal close-packed(HCP) crystal structure or a face centered cubic (FCC) crystalstructure. When the first non-magnetic pattern 150 has the hexagonalclose-packed (HCP) crystal structure, the first non-magnetic pattern 150may be provided to have a (0001) plane parallel to the interface betweenthe tunnel barrier pattern TBR and the free magnetic structure FMS. Whenthe first non-magnetic pattern 150 has the face centered cubic (FCC)crystal structure, the first non-magnetic pattern 150 may be provided tohave a (111) plane parallel to the interface between the tunnel barrierpattern TBR and the free magnetic structure FMS. In some embodiments,the interface between the tunnel barrier pattern TBR and the freemagnetic structure FMS may be substantially parallel to the top surfaceof the substrate 100. Thus, a (0001) plane of the first non-magneticpattern 150 having a hexagonal close-packed (HCP) crystal structure, ora (111) plane of the first non-magnetic pattern 150 having a facecentered cubic (FCC) crystal structure may be substantially parallel tothe top surface of the substrate 100. As described with reference toFIG. 5A, when viewed in a plan view (e.g., when viewed in a plan viewparallel to the top surface of the substrate 100), atoms in the firstnon-magnetic pattern 150 may be arranged to have 6-fold symmetry. Thatis, when viewed in a plan view, the arrangement of atoms in the firstnon-magnetic pattern 150 may have the same symmetry as the arrangementof atoms in the first magnetic pattern 140. The first non-magneticpattern 150 may include at least one of Ir, Rh, Pd, Ag, Ru, Y, Sc, Zr,Hf, Ti or Re.

The second magnetic pattern 142 may be in contact with the tunnelbarrier pattern TBR. Such a contact between the second magnetic pattern142 and the tunnel barrier pattern TBR may induce magnetic anisotropy,allowing the second magnetic pattern 142 to have a perpendicularmagnetization property. The second magnetic pattern 142 may beferromagnetically coupled to the first magnetic pattern 140. That is, amagnetization direction 142 m of the second magnetic pattern 142 may beparallel to the magnetization direction 140 m of the first magneticpattern 140. The magnetization directions 130 m of the second pinnedpattern 130 may be determined by the magnetization directions 140 m and142 m of the first and second magnetic patterns 140 and 142. A crystalstructure of the second magnetic pattern 142 may be different fromcrystal structures of the first magnetic pattern 140 and the firstnon-magnetic pattern 150. The second magnetic pattern 142 may have abody centered cubic (BCC) crystal structure. A (001) plane of the secondmagnetic pattern 142 having the body centered cubic (BCC) crystalstructure may be provided to be parallel to the interface between thetunnel barrier pattern TBR and the free magnetic structure FMS. In someembodiments, the interface between the tunnel barrier pattern TBR andthe free magnetic structure FMS may be substantially parallel to the topsurface of the substrate 100. Thus, a (001) plane of the second magneticpattern 142 having a body centered cubic (BCC) crystal structure may besubstantially parallel to the top surface of the substrate 100.

Referring to FIG. 5B, when viewed in a plan view (e.g., when viewed in aplan view parallel to the top surface of the substrate 100), atoms inthe second magnetic pattern 142 may be arranged to have a 4-foldsymmetry. A line L2 shown in FIG. 5B is a virtual line representing acrystal plane lattice, a line S2 is a virtual line representing anatomic arrangement of the 4-fold symmetry. For example, the secondmagnetic pattern 142 may include iron (Fe). The second magnetic pattern142 may include a magnetic material that induces magnetic anisotropy atan interface between the second magnetic pattern 142 and the tunnelbarrier pattern TBR. For example, the second magnetic pattern 142 mayinclude cobalt-iron-boron (CoFeB).

The second non-magnetic pattern 152 may have the same crystal structureas the second magnetic pattern 142. The second non-magnetic pattern 152may have a body centered cubic (BCC) crystal structure. A (001) plane ofthe second non-magnetic pattern 152 having the body centered cubic (BCC)crystal structure may be provided to be parallel to the interfacebetween the tunnel barrier pattern TBR and the free magnetic structureFMS. In some embodiments, the interface between the tunnel barrierpattern TBR and the free magnetic structure FMS may be substantiallyparallel to the top surface of the substrate 100. Thus, a (001) plane ofthe second non-magnetic pattern 152 having a body centered cubic (BCC)crystal structure may be substantially parallel to the top surface ofthe substrate 100. As described with reference to FIG. 5B, when viewedin a plan view (e.g., when viewed in a plan view parallel to the topsurface of the substrate 100), atoms in the second non-magnetic pattern152 may be arranged to have the 4-fold symmetry. That is, an arrangementof atoms in the second non-magnetic pattern 152 may have the samesymmetry as an arrangement of atoms in the second magnetic pattern 142.The second non-magnetic pattern 152 may include at least one of W, Mo,Nb, Ta or V.

One surface of the third magnetic pattern 144 may be in contact with thefirst non-magnetic pattern 150, and the other surface of the thirdmagnetic pattern 144 may be in contact with the second non-magneticpattern 152. The one surface and the other surface of the third magneticpattern 144 may be opposite to each other. The third magnetic pattern144 may include, for example, boron (B). Since the third magneticpattern 144 is interposed between the first non-magnetic pattern 150 andthe second non-magnetic pattern 152, boron (B) in the third magneticpattern 144 may be prevented (or suppressed) from being diffused intomagnetic patterns (e.g., the first and second magnetic patterns 140 and142) adjacent thereto during a thermal treatment process. In someembodiments, at least a portion of the third magnetic pattern 144 may beamorphous. The third magnetic pattern 144 may include, for example,iron-boron (FeB).

In some embodiments, a crystal structure of lower patterns (e.g., thefirst non-magnetic pattern 150 and the first magnetic pattern 140) underthe third magnetic pattern 144 may be different from a crystal structureof upper patterns (i.e., the second non-magnetic pattern 152 and thesecond magnetic pattern 142) over the third magnetic pattern 144. Thethird magnetic pattern 144 may be provided between the firstnon-magnetic pattern 150 and the second non-magnetic pattern 152 havingdifferent crystal structures from each other.

The first non-magnetic pattern 150 may have a hexagonal close-packed(HCP) crystal structure or a face centered cubic (FCC) crystalstructure, and when viewed in a plan view, an arrangement of atoms inthe first non-magnetic pattern 150 may be provided to have the samesymmetry as an arrangement of atoms in the first magnetic pattern 140.In this case, at an interface between the first non-magnetic pattern 150and the first magnetic pattern 140, a magnetic moment of atoms in thefirst non-magnetic pattern 150 may be higher than when the firstnon-magnetic pattern 150 has a body centered cubic (BCC) crystalstructure. Thus, a ferromagnetic coupling between the first magneticpattern 140 and the second magnetic pattern 142 may be enhanced.Therefore, stability of magnetization of the reference magneticstructure RMS may be increased.

The second non-magnetic pattern 152 may have the same crystal structureas the second magnetic pattern 142. When viewed in a plan view, anarrangement of atoms in the second non-magnetic pattern 152 may beprovided to have the same symmetry as an arrangement of atoms in thesecond magnetic pattern 142. In this case, the magnetic anisotropy ofthe second magnetic pattern 142 induced by a contact between the secondmagnetic pattern 142 and the tunnel barrier pattern TBR may be improved.Thus, tunneling magnetoresistance ratio (TMR) of the magnetic tunneljunction pattern MTJ may be improved.

In the case where at least a portion of the third magnetic pattern 144is amorphous, it is possible to suppress that a crystal structure of thelower patterns (e.g., the first non-magnetic pattern 150 and the firstmagnetic pattern 140) under the third magnetic pattern 144 affects acrystal growth of the upper patterns (i.e., the second non-magneticpattern 152 and the second magnetic pattern 142) over the third magneticpattern 144. Accordingly, the magnetic anisotropy of the second magneticpattern 142 may be improved, and as a result, the tunnelingmagnetoresistance ratio (TMR) of the magnetic tunnel junction patternMTJ may be improved. In the case where a thickness of the third magneticpattern 144 is increased, it is possible to further reduce or minimizethat the crystal structure of the lower patterns affects the crystalgrowth of the upper patterns. However, a ferromagnetic coupling betweenthe first magnetic pattern 140 and the second magnetic pattern 142 maybe weakened. According to embodiments of the inventive concepts, eventhough the thickness of the third magnetic pattern 144 is increased, thefirst non-magnetic pattern 150 may suppress weakening of theferromagnetic coupling between the first magnetic pattern 140 and thesecond magnetic pattern 142. Accordingly, it is possible to provide amagnetic memory device capable of increasing the stability ofmagnetization of the reference magnetic structure RMS, and improving thetunneling magnetoresistance ratio of the magnetic tunnel junctionpattern MTJ.

Referring back to FIG. 3, the reference magnetic structure RMS mayfurther include a seed pattern 106 between the bottom electrode BE andthe first pinned pattern 110. The seed pattern 106 may include amaterial contributing to a crystal growth of the first pinned pattern110. In some embodiments, the seed pattern 106 may include a conductivematerial having the same crystal structure as the first pinned pattern110. For example, the seed pattern 106 may include ruthenium (Ru).

The tunnel barrier pattern TBR may include at least one of magnesiumoxide, titanium oxide, aluminum oxide, magnesium-zinc oxide,magnesium-boron oxide, titanium nitride or vanadium nitride. As anexample, the tunnel barrier pattern TBR may include a magnesium oxidelayer having a sodium chloride (NaCl) crystal structure.

The free magnetic structure FMS may include a free magnetic pattern 170and a capping oxide pattern 180. The free magnetic pattern 170 may beprovided between the tunnel barrier pattern TBR and the capping oxidepattern 180, and the capping oxide pattern 180 may be provided betweenthe free magnetic pattern 170 and the top electrode TE.

The free magnetic pattern 170 may be in contact with the tunnel barrierpattern TBR. The free magnetic pattern 170 may exhibit a perpendicularmagnetization property, which results from magnetic anisotropy inducedby a contact between the free magnetic pattern 170 and the tunnelbarrier pattern TBR. A magnetization direction 170 m of the freemagnetic pattern 170 may be changed to be parallel or anti-parallel tothe magnetization direction 130 m of the second pinned pattern 130. Aresistance value of the magnetic tunnel junction pattern MTJ may bedependent on the relative magnetization directions of the second pinnedpattern 130 and the free magnetic pattern 170. For example, the magnetictunnel junction pattern MTJ may have a first resistance value when themagnetization direction 130 m of the second pinned pattern 130 isparallel to the magnetization direction 170 m of the free magneticpattern 170. The magnetic tunnel junction pattern MTJ may have a secondresistance value higher than the first resistance value when themagnetization direction 130 m of the second pinned pattern 130 isanti-parallel to the magnetization direction 170 m of the free magneticpattern 170.

The free magnetic pattern 170 may include a magnetic material thatinduces the magnetic anisotropy at an interface between the freemagnetic pattern 170 and the tunnel barrier pattern TBR. For example,the free magnetic pattern 170 may include cobalt-iron-boron (CoFeB).

The capping oxide pattern 180 may be in contact with the free magneticpattern 170. The magnetic anisotropy may be induced at an interfacebetween the capping oxide pattern 180 and the free magnetic pattern 170.As an example, oxygen atoms in the capping oxide pattern 180 may reactwith iron atoms in the free magnetic pattern 170 and the magneticanisotropy may be induced by a bond between the oxygen atoms and ironatoms. Accordingly, the magnetic anisotropy of the free magnetic pattern170 may be improved. The capping oxide pattern 180 may include, forexample, magnesium oxide (MgO), tantalum oxide (TaO) and/or aluminumoxide (AlO).

A upper interlayer insulating layer 190 may be provided on the lowerinterlayer insulating layer 102 to extend on or cover the bottomelectrode BE, the magnetic tunnel junction pattern MTJ and the topelectrode TE. An upper contact plug 192 may be connected to the topelectrode TE through the upper interlayer insulating layer 190.

The upper interlayer insulating layer 190 may include oxide, nitrideand/or oxynitride, and the upper contact plug 192 may include at leastone of metals (e.g., titanium, tantalum, copper, aluminum or tungsten)or conductive metal nitrides (e.g., titanium nitride or tantalumnitride). An interconnection line 194 may be provided on the upperinterlayer insulating layer 190. The interconnection line 194 may beconnected to the upper contact plug 192. The interconnection line 194may include at least one of metals (e.g., titanium, tantalum, copper,aluminum or tungsten) or conductive metal nitrides (e.g., titaniumnitride or tantalum nitride). In some embodiments, the interconnectionline 194 may serve as a bit line.

FIGS. 6 and 7 are cross-sectional views illustrating a method forfabricating a magnetic memory device according to some embodiments ofthe inventive concepts.

Referring to FIG. 6, a lower interlayer insulating layer 102 may beformed on a substrate 100. The substrate 100 may include a semiconductorsubstrate. For example, the substrate 100 may include a siliconsubstrate, a germanium substrate, a silicon-germanium substrate and soon. In some embodiments, selection elements may be formed on thesubstrate 100, and the lower interlayer insulating layer 102 may beformed to extend on or cover the selection elements. The selectionelements may be field effect transistors. Alternatively, the selectionelements may be diodes. The lower interlayer insulating layer 102 may beformed to have a single- or multi-layered structure including oxide,nitride and/or oxynitride. The lower contact plug 104 may be formed inthe lower interlayer insulating layer 102. The lower contact plug 104may be formed to penetrate the lower interlayer insulating layer 102,and may be electrically connected to a terminal of a corresponding oneof the selection elements. The lower contact plug 104 may include atleast one of doped semiconductor materials (e.g., doped silicon), metals(e.g., tungsten, titanium and/or tantalum), conductive metal nitrides(e.g., titanium nitride, tantalum nitride and/or tungsten nitride) ormetal-semiconductor compounds (e.g., metal silicide).

A bottom electrode layer BEL may be formed on the lower interlayerinsulating layer 102. The bottom electrode layer BEL may includeconductive metal nitrides, such as titanium nitride and/or tantalumnitride. A seed layer 106L may be formed on the bottom electrode layerBEL. The seed layer 106L may include materials (e.g., ruthenium (Ru))contributing to crystal growth of magnetic layers formed thereon. Thebottom electrode layer BEL and the seed layer 106L may be formed by asputtering process, a chemical vapor deposition process, an atomic layerdeposition process and so on.

A first pinned layer 110L, an exchange coupling layer 120L and a secondpinned layer 130L may be stacked on the seed layer 106L. Specifically,the first pinned layer 110L may be formed on the seed layer 106L. Thefirst pinned layer 110L may be formed using the seed layer 106L as aseed. The first pinned layer 110L may have the same crystal structure asthe seed layer 106L. For example, the seed layer 106L may includeruthenium (Ru) having a hexagonal close-packed crystal structure, andthe first pinned layer 110L may include a cobalt-platinum (CoPt) alloyhaving a hexagonal close-packed crystal structure or [Co/Pt]n (where nis the number of stacked pairs of layers). The exchange coupling layer120L may be formed on the first pinned layer 110L. The exchange couplinglayer 120L may be formed using the first pinned layer 110L as a seed.For example, the exchange coupling layer 120L may include ruthenium (Ru)having a hexagonal close-packed crystal structure.

The second pinned layer 130L may be formed on the exchange couplinglayer 120L. The second pinned layer 130L may include a first magneticlayer 140L, a first non-magnetic layer 150L, a third magnetic layer 144,a second non-magnetic layer 152L and a second magnetic layer 142L whichare sequentially stacked on the exchange coupling layer 120L.Specifically, the first magnetic layer 140L may be formed on theexchange coupling layer 120L. The first magnetic layer 140L may beformed using the exchange coupling layer 120L as a seed. The firstmagnetic layer 140L may be formed to have a hexagonal close-packed (HCP)crystal structure or a face centered cubic (FCC) crystal structure, anda (0001) plane of the HCP crystal structure or a (111) plane of the FCCcrystal structure may be parallel to a top surface of the substrate 100.For example, the first magnetic layer 140L may include at least one ofcobalt (Co) or nickel (Ni). The first non-magnetic layer 150L may beformed on the first magnetic layer 140L. The first non-magnetic layer150L may be formed using the first magnetic layer 140L as a seed. Thefirst non-magnetic layer 150L may be formed to have a hexagonalclose-packed (HCP) crystal structure or a face centered cubic (FCC)crystal structure, and a (0001) plane of the HCP crystal structure or a(111) plane of the FCC crystal structure may be parallel to the topsurface of the substrate 100. For example, the first non-magnetic layer150L may include at least one of Ir, Rh, Pd, Ag, Ru, Y, Sc, Zr, Hf, Tior Re. The third magnetic layer 144L may be formed on the firstnon-magnetic layer 150L. The third magnetic layer 144L may be formed inan amorphous state during a deposition process. The third magnetic layer144L may include, for example, boron-doped iron (e.g., iron-boron(FeB)). The second non-magnetic layer 152L may be formed on the thirdmagnetic layer 144L. The second non-magnetic layer 152L may be formed tohave a body centered cubic (BCC) crystal structure, and a (001) plane ofthe BCC crystal structure may be parallel to the top surface of thesubstrate 100. For example, the second non-magnetic layer 152L mayinclude at least one of W, Mo, Nb, Ta or V. The second magnetic layer142L may be formed on the second non-magnetic layer 152L. The secondmagnetic layer 142L may be formed in an amorphous state during adeposition process. The second magnetic layer 142L may include adifferent material from that of the third magnetic layer 144L. Forexample, the second magnetic layer 142L may include cobalt-iron-boron(CoFeB). The second magnetic layer 142L may be formed using a sputteringprocess, a chemical vapor deposition process or an atomic layerdeposition process.

A tunnel barrier layer TBRL may be formed on the second pinned layer130. The tunnel barrier layer TBRL may include at least one of magnesium(Mg) oxide, titanium (Ti) oxide, aluminum (Al) oxide, magnesium-zinc(Mg—Zn) oxide, or magnesium-boron (Mg—B) oxide. The tunnel barrier layerTBRL may be formed using, for example, a sputtering process.

A free magnetic layer 170L and a capping oxide layer 180L may besequentially formed on the tunnel barrier layer TBRL. The free magneticlayer 170L may be formed in an amorphous state during a depositionprocess. The free magnetic layer 170L may include, for example,cobalt-iron-boron (CoFeB). The free magnetic layer 170L may be formedusing a sputtering process, a chemical vapor deposition process or anatomic layer deposition process. The capping oxide layer 180L mayinclude, for example, magnesium oxide (MgO), tantalum oxide (TaO) and/oraluminum oxide (AlO). The capping oxide layer 180L may be formed using asputtering process.

After the capping oxide layer 180L is formed, a thermal treatmentprocess (H) may be performed. The thermal treatment process H may alsobe performed after forming the free magnetic layer 170L and beforeforming the capping oxide layer 180L. The second magnetic layer 142L andthe free magnetic layer 170L may be crystallized by the thermaltreatment process H. The crystallized second magnetic layer 142L mayhave the same crystal structure as the second non-magnetic layer 152L.The crystallized second magnetic layer 142L may be crystallized usingthe tunnel barrier layer TBRL as a seed during the thermal heattreatment process H. For example, the tunnel barrier layer TBRL may havea sodium chloride-type crystal structure, and the crystallized secondmagnetic layer 142L may have a body centered cubic (BCC) crystalstructure. The crystallized free magnetic layer 170L may have the samecrystal structure as the crystallized second magnetic layer 142L. Thecrystallized free magnetic layer 170L may be crystallized using thetunnel barrier layer TBRL as a seed during the thermal treatment processH. For example, the tunnel barrier layer TBRL may have a sodiumchloride-type crystal structure, and the crystallized free magneticlayer 170L may have a body centered cubic (BCC) crystal structure.

At least a portion of the third magnetic layer 144L may be in anamorphous state even after the thermal treatment process H. As the thirdmagnetic layer 144L may be interposed between the first and secondnon-magnetic layers 150L and 152L, boron (B) in the third magnetic layer144L may be prevented (or suppressed) from being diffused out of thethird magnetic layer 144L during the thermal treatment process H.Accordingly, at least a portion of the third magnetic layer 144L mayremain in an amorphous state even after the thermal treatment process H.

Referring to FIG. 7, a conductive mask pattern 200 may be formed on thecapping oxide layer 180L. The conductive mask pattern 200 may include atleast one of tungsten, titanium, tantalum, aluminum or metal nitrides(e.g., titanium nitride or tantalum nitride). The conductive maskpattern 200 may be used to define a position and a shape for forming amagnetic tunnel junction pattern to be described later. The cappingoxide layer 180L, the free magnetic layer 170L, the tunnel barrier layerTBRL, the second pinned layer 130L, the exchange coupling layer 120L,the first pinned layer 110L, the seed layer 106L and the bottomelectrode layer BEL may be sequentially etched using the conductive maskpattern 200 as an etch mask. The etching process may be performed using,for example, an ion beam etching process. As a result of the etchingprocess, a bottom electrode BE, a seed pattern 106, a first pinnedpattern 110, an exchange coupling pattern 120, a second pinned pattern130, a tunnel barrier pattern TBR, a free magnetic pattern 170 and acapping oxide pattern 180 may be sequentially formed on the lowerinterlayer insulating layer 102. The second pinned pattern 130 mayinclude a first magnetic pattern 140 adjacent the exchange couplingpattern 120, a second magnetic pattern 142 adjacent the tunnel barrierpattern TBR, a third magnetic pattern 144 between the first magneticpattern 140 and a second magnetic pattern 142, a first non-magneticpattern 150 between the first magnetic pattern 140 and the thirdmagnetic pattern 144, and a second non-magnetic pattern 152 between thesecond magnetic pattern 142 and the third magnetic pattern 144. The seedpattern 106, the first pinned pattern 110, the exchange coupling pattern120 and the second pinned pattern 130 may constitute or define areference magnetic structure RMS. The free magnetic pattern 170 and thecapping oxide pattern 180 may constitute or define a free magneticstructure FMS. The reference magnetic structure RMS, the free magneticstructure FMS, and the tunnel barrier pattern TBR therebetween mayconstitute or define a magnetic tunnel junction pattern MTJ. The bottomelectrode BE may be electrically connected to the lower contact plug 104formed in the lower interlayer insulating layer 102. The conductive maskpattern 200 may serve as a top electrode TE. The magnetic tunneljunction pattern MTJ may be formed between the bottom electrode BE andthe top electrode TE.

Referring back to FIG. 3, the upper interlayer insulating layer 190 maybe formed on the lower interlayer insulating layer 102 so as to extendon or cover the bottom electrode BE, the magnetic tunnel junctionpattern MTJ and the top electrode TE. The upper contact plug 192 may beformed to penetrate the upper interlayer insulating layer 190, and maybe connected to the top electrode TE. An interconnection line 194 may beformed on the upper interlayer insulating layer 190. The interconnectionline 194 may be connected to the upper contact plug 192. In someembodiments, the interconnection line 194 may serve as a bit line.

FIG. 8 is a cross-sectional view illustrating a magnetic memory deviceaccording to some embodiments of the inventive concepts. In thefollowing description, an element previously described with reference toFIGS. 3, 4, 5A and 5B may be identified by a similar or identicalreference number without repeating an overlapping description thereof,for the sake of brevity.

Referring to FIG. 8, a lower interlayer insulating layer 102 may beprovided on a substrate 100. Selection elements may be provided on thesubstrate 100, and the lower interlayer insulating layer 102 may beprovided to extend on or cover the selection elements. A lower contactplug 104 may be provided in the lower interlayer insulating layer 102.The lower contact plug 104 may be provided to penetrate the lowerinterlayer insulating layer 102, and may be electrically connected to aterminal of a corresponding one of selection elements.

A bottom electrode BE may be provided on the lower interlayer insulatinglayer 102. The bottom electrode BE may be electrically connected to thelower contact plug 104. A reference magnetic structure RMS and a freemagnetic structure FMS may be stacked on the lower interlayer insulatinglayer 102. A tunnel barrier pattern TBR may be provided between thereference magnetic structure RMS and the free magnetic structure FMS. Insome embodiments, the free magnetic structure FMS may be providedbetween the bottom electrode BE and the tunnel barrier pattern TBR.

The reference magnetic structure RMS may include at least one fixedlayer having a fixed magnetization direction, and the free magneticstructure FMS may include at least one free layer having a switchablemagnetization direction. The reference magnetic structure RMS, the freemagnetic structure FMS and the tunnel barrier pattern TBR may constituteor define a magnetic tunnel junction pattern MTJ. The magnetizationdirections of the fixed layer and the free layer may be substantiallyperpendicular to an interface between the tunnel barrier pattern TBR andthe free magnetic structure FMS. That is, the magnetic tunnel junctionpattern MTJ may be a perpendicular magnetization-type magnetic tunneljunction pattern.

A top electrode TE may be provided on the magnetic tunnel junctionpattern MTJ. The magnetic tunnel junction pattern MTJ may be disposedbetween the bottom electrode BE and the top electrode TE. In someembodiments, the reference magnetic structure RMS may be providedbetween the tunnel barrier pattern TBR and the top electrode TE. Thebottom electrode BE, the magnetic tunnel junction pattern MTJ and thetop electrode TE may be provided to have a vertical-aligned sidewalls.

The free magnetic structure FMS may include a free magnetic pattern 170between the bottom electrode BE and the tunnel barrier pattern TBR. Insome embodiments, the bottom electrode BE may include a materialcontributing to crystal growth of the free magnetic pattern 170. Thefree magnetic pattern 170 may be in contact with the tunnel barrierpattern TBR. The free magnetic pattern 170 may exhibit a perpendicularmagnetization property, which results from magnetic anisotropy inducedby a contact between the free magnetic pattern 170 and the tunnelbarrier pattern TBR. The free magnetic pattern 170 may include amagnetic material that induces magnetic anisotropy at an interfacebetween the free magnetic pattern 170 and the tunnel barrier patternTBR. For example, the free magnetic pattern 170 may includecobalt-iron-boron (CoFeB).

The reference magnetic structure RMS may include a syntheticantiferromagnetic (SAF) structure. For example, the reference magneticstructure RMS may include a first pinned pattern 110 between the tunnelbarrier pattern TBR and the top electrode TE, a second pinned pattern130 between the first pinned pattern 110 and the tunnel barrier patternTBR, and an exchange coupling pattern 120 between the first pinnedpattern 110 and the second pinned pattern 130. The exchange couplingpattern 120 may couple the first pinned pattern 110 to the second pinnedpattern 130 in such a way that a magnetization direction 110 m of thefirst pinned pattern 110 is anti-parallel to a magnetization direction130 m of the second pinned pattern 130. The exchange coupling pattern120 may include, for example, ruthenium (Ru). The first pinned pattern110 may include substantially the same material as the first pinnedpattern 110 according to some embodiments described with reference toFIG. 3.

The second pinned pattern 130 may include a first magnetic pattern 140adjacent the exchange coupling pattern 120, a second magnetic pattern142 adjacent the tunnel barrier pattern TBR, a third magnetic pattern144 between the first magnetic pattern 140 and the second magneticpattern 142, a first non-magnetic pattern 150 between the first magneticpattern 140 and the third magnetic pattern 144, and a secondnon-magnetic pattern 152 between the second magnetic pattern 142 and thethird magnetic pattern 144. The first to third magnetic patterns 140,142 and 144 and the first and second non-magnetic patterns 150 and 152may be substantially the same as the first to third magnetic patterns140, 142 and 144 and the first and second non-magnetic patterns 150 and152 according to some embodiments described with reference to FIGS. 3,4, 5A and 5B.

A magnetization direction 170 m of the free magnetic pattern 170 may bechanged to be parallel or anti-parallel to the magnetization direction130 m of the second pinned pattern 130. A resistance value of themagnetic tunnel junction pattern MTJ may be dependent on the relativemagnetization directions of the second pinned pattern 130 and the freemagnetic pattern 170. For example, the magnetic tunnel junction patternMTJ may have a first resistance value when the magnetization direction130 m of the second pinned pattern 130 is parallel to the magnetizationdirection 170 m of the free magnetic pattern 170. The magnetic tunneljunction pattern MTJ may have a second resistance value higher than thefirst resistance value when the magnetization direction 130 m of thesecond pinned pattern 130 is anti-parallel to the magnetizationdirection 170 m of the free magnetic pattern 170.

The upper interlayer insulating layer 190 may be provided on the lowerinterlayer insulating layer 102 to extend on or cover the bottomelectrode BE, the magnetic tunnel junction pattern MTJ and the topelectrode TE. The upper contact plug 192 may be provided to penetratethe upper interlayer insulating layer 190, and may be connected to thetop electrode TE. An interconnection line 194 may be provided on theupper interlayer insulating layer 190, and may be connected to the uppercontact plug 192. In some embodiments, the interconnection line 194 mayserve as a bit line.

FIGS. 9 to 11 are cross-sectional views illustrating a method forfabricating a magnetic memory device according to some embodiments ofthe inventive concepts. In the following description, an elementpreviously described with reference to FIGS. 6 and 7 may be identifiedby a similar or identical reference number without repeating anoverlapping description thereof, for the sake of brevity.

Referring to FIG. 9, a lower interlayer insulating layer 102 may beformed on a substrate 100. Selection elements may be formed on thesubstrate 100, and the lower interlayer insulating layer 102 may beformed to extend on or cover the selection elements. A lower contactplug 104 may be formed in the lower interlayer insulating layer 102. Thelower contact plug 104 may be formed to penetrate the lower interlayerinsulating layer 102, and may be electrically connected to a terminal ofcorresponding one of the selection elements.

A bottom electrode layer BEL may be formed on the lower interlayerinsulating layer 102. The bottom electrode layer BEL may includeconductive metal nitrides, such as titanium nitride and/or tantalumnitride. According to some embodiments, the bottom electrode layer BELmay further include a material contributing to crystal growth ofmagnetic layers formed thereon. A free magnetic layer 170L may be formedon the bottom electrode layer BEL. The free magnetic layer 170L may bein an amorphous state during a deposition process. The free magneticlayer 170L may include, for example, cobalt-iron-boron (CoFeB). A tunnelbarrier layer TBRL may be formed the free magnetic layer 170L. Thetunnel barrier layer TBRL may be the same as the tunnel barrier layerTBRL described with reference to FIG. 6.

A second magnetic layer 142L may be formed on the tunnel barrier layerTBRL. The second magnetic layer 142L may be in an amorphous state duringa deposition process. The second magnetic layer 142L may include thesame material as the second magnetic layer 142L. The second magneticlayer 142L may include, for example, cobalt-iron-boron (CoFeB).

In some embodiments, a thermal treatment process H may be performedafter forming the second magnetic layer 142L. The second magnetic layer142L and the free magnetic layer 170L may be crystallized by the thermaltreatment process H. The crystallized free magnetic layer 170L may havethe same crystal structure as the crystallized second magnetic layer142L. The crystallized free magnetic layer 170L and the crystallizedsecond magnetic layer 142L may be crystallized using the tunnel barrierlayer TBRL as a seed during the thermal treatment process H. Forexample, the tunnel barrier layer TBRL may have a sodium chloride-typecrystal structure, and the crystallized free magnetic layer 170L and thecrystallized second magnetic layer 142L may have a body centered cubic(BCC) crystal structure. In other embodiments, the thermal treatmentprocess H may be performed after forming magnetic and non-magneticlayers to be described later.

Referring to FIG. 10, a second non-magnetic layer 152L may be formed onthe second magnetic layer 142L. The second non-magnetic layer 152L mayhave the same crystal structure as the second magnetic layer 142L. Thesecond non-magnetic layer 152L may be formed to have a body centeredcubic (BCC) crystal structure, a (001) plane of the body centered cubic(BCC) crystal structure may be parallel to a top surface of thesubstrate 100. The second non-magnetic layer 152L may include, forexample, at least one of W, Mo, Nb, Ta or V. The third magnetic layer144L may be formed on the second non-magnetic layer 152L. The thirdmagnetic layer 144L may be formed in an amorphous state during adeposition process. For example, the third magnetic layer 144L mayinclude, for example, boron-doped iron (e.g., iron-boron (FeB)). A firstnon-magnetic layer 150L may be formed on the third magnetic layer 144L.The first non-magnetic layer 150L may be formed to have a hexagonalclose-packed (HCP) crystal structure or a face centered cubic (FCC)crystal structure, and a (0001) plane of the HCP crystal structure or a(111) plane of the FCC crystal structure may be parallel to the topsurface of the substrate 100. For example, the first non-magnetic layer150L may include at least one of Ir, Rh, Pd, Ag, Ru, Y, Sc, Zr, Hf, Tior Re. A first magnetic layer 140L may be formed on the firstnon-magnetic layer 150L. The first magnetic layer 140L may be formedusing the first non-magnetic layer 150L as a seed. The first magneticlayer 140L may be formed to have a hexagonal close-packed (HCP) crystalstructure or a face centered cubic (FCC) crystal structure, and a (0001)plane of the HCP crystal structure or a (111) plane of the FCC crystalstructure may be parallel to the top surface of the substrate 100. Forexample, the first magnetic layer 140L may include at least one ofcobalt (Co) or nickel (Ni). The first to third magnetic layers 140L,142L and 144L, and the first and second non-magnetic layers 150L and152L may constitute or define a second pinned layer 130L.

An exchange coupling layer 120L may be formed on the second pinned layer130L. The exchange coupling layer 120L may be formed using the firstmagnetic layer 140L as a seed. For example, the exchange coupling layer120L may include ruthenium (Ru) having a hexagonal close-packed crystalstructure. A first pinned layer 110L may be formed on the exchangecoupling layer 120L. The first pinned layer 110L may be formed using theexchange coupling layer 120L as a seed. The first pinned layer 110L mayinclude a cobalt-platinum (CoPt) alloy having a hexagonal close-packedcrystal structure or [Co/Pt]n (where n is the number of stacked pairs oflayers).

In some embodiments, the thermal treatment process H, described withreference to FIG. 9, may be performed after forming the first pinnedlayer 110L. In this case, as described with reference to FIG. 9, thesecond magnetic layer 142L and the free magnetic layer 170L may becrystallized by the thermal treatment process H. At least a portion ofthe third magnetic layer 144L may be in an amorphous state even afterthe thermal treatment process. Since the third magnetic layer 144L maybe interposed between the first and second non-magnetic layers 150L and152L, boron (B) in the third magnetic layer 144L may be prevented (orsuppressed) from being diffused out of the third magnetic layer 144Lduring the thermal treatment process H. Accordingly, at least a portionof the third magnetic layer 144L may remain in an amorphous state evenafter the thermal treatment process H.

Referring to FIG. 11, a conductive mask pattern 200 may be formed on thefirst pinned layer 110L. The conductive mask pattern 200 may be used todefine a position and a shape for forming a magnetic tunnel junctionpattern to be described later. The first pinned layer 110L, the exchangecoupling layer 120L, the second pinned layer 130L, the tunnel barrierlayer TBRL, the free magnetic layer 170L, and the bottom electrode layerBEL may be sequentially etched using the conductive mask pattern 200 asan etch mask. As a result of the etching process, a bottom electrode BE,a free magnetic pattern 170, a tunnel barrier pattern TBR, a secondpinned pattern 130, an exchange coupling pattern 120, and a first pinnedpattern 110 may be sequentially formed on the lower interlayerinsulating layer 102. The second pinned pattern 130 may include a firstmagnetic pattern 140 adjacent the exchange coupling pattern 120, asecond magnetic pattern 142 adjacent the tunnel barrier pattern TBR, athird magnetic pattern 144 between the first magnetic pattern 140 and asecond magnetic pattern 142, a first non-magnetic pattern 150 betweenthe first magnetic pattern 140 and the third magnetic pattern 144, and asecond non-magnetic pattern 152 between the second magnetic pattern 142and the third magnetic pattern 144. The first pinned pattern 110, theexchange coupling pattern 120 and the second pinned pattern 130 mayconstitute or define a reference magnetic structure RMS. The freemagnetic pattern 170 may constitute or define a free magnetic structureFMS. The reference magnetic structure RMS, the free magnetic structureFMS, and the tunnel barrier pattern TBR therebetween may constitute ordefine a magnetic tunnel junction pattern MTJ. The bottom electrode BEmay be electrically connected to the lower contact plug 104 formed inthe lower interlayer insulating layer 102. The conductive mask pattern200 may serve as a top electrode TE. The magnetic tunnel junctionpattern MTJ may be formed between the bottom electrode BE and the topelectrode TE.

A subsequent process may be performed in substantially the same manneras that of the method described with reference to FIG. 3.

According to embodiments of the inventive concepts, a reference magneticstructure of a magnetic tunnel junction pattern may include a firstmagnetic pattern, a second magnetic pattern, a third magnetic patternbetween the first magnetic pattern and the second magnetic pattern, afirst non-magnetic pattern between the first magnetic pattern and thethird magnetic pattern, and a second non-magnetic pattern between thesecond magnetic pattern and the third magnetic pattern. At least aportion of the third magnetic pattern may be in an amorphous state, andthe first non-magnetic pattern and the second non-magnetic pattern mayhave a different crystal structure from each other.

The first non-magnetic pattern may have a hexagonal close-packed (HCP)crystal structure or a face centered cubic (FCC) crystal structure. Whenviewed in a plan view, an arrangement of atoms in the first non-magneticpattern may be provided to have the same symmetry as an arrangement ofatoms in the first magnetic pattern. In this case, a magnetic moment ofatoms in the first non-magnetic pattern may be relatively high at aninterface between the first non-magnetic pattern and the first magneticpattern.

The second non-magnetic pattern may be provided to have the same crystalstructure (for example, body centered cubic (BCC) crystal structure) asthe second magnetic pattern. When viewed in a plan view, an arrangementof atoms in the second non-magnetic pattern may be provided to have thesame symmetry as an arrangement of atoms in the second magnetic pattern.In this case, the magnetic anisotropy of the second magnetic patterninduced by a contact between the second magnetic pattern and the tunnelbarrier pattern may be improved. When at least a portion of the thirdmagnetic pattern is amorphous, it is possible to suppress that a crystalstructure of lower patterns (e.g., the first non-magnetic pattern andthe first magnetic pattern) under the third magnetic pattern affectscrystal growth of upper patterns (e.g., the second non-magnetic patternand the second magnetic pattern) over the third magnetic pattern.

Accordingly, it is possible to provide a magnetic memory device capableof increasing the stability of magnetization of the reference magneticstructure RMS, and improving the tunneling magnetoresistance ratio ofthe magnetic tunnel junction MTJ.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. It will be understood that when an element is referred toas being “on” or “connected to” or “adjacent” another element (e.g., alayer or substrate), it can be directly on or connected to or adjacentthe other element, or intervening elements may also be present. Incontrast, when an element is referred to as being “directly on” or“directly connected to” or “immediately adjacent” another element, thereare no intervening elements present.

It will also be understood that, although the terms first, second, etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another element. Thus, a first element discussed belowcould be termed a second element without departing from the scope of thepresent inventive concepts.

It will be understood that spatially relative terms, such as “beneath,”“below,” “lower,” “above,” “upper” and the like, are intended toencompass different orientations of the device in use or operation inaddition to the orientation depicted in the figures. For example, if thedevice in the figures is turned over, elements described as “below” or“beneath” other elements or features would then be oriented “above” theother elements or features. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The use of the terms “a” and “an” and “the” and similar referencesherein are to be construed to cover both the singular and the plural,unless otherwise indicated herein or clearly contradicted by context.The terms “comprising,” “having,” “including,” and “containing” are tobe construed as open-ended terms (i.e., meaning “including, but notlimited to,”) unless otherwise noted. The term “and/or” includes any andall combinations of one or more of the associated listed items.

While the inventive concepts have been described with reference toexample embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the inventive concepts. Therefore, itshould be understood that the above embodiments are not limiting, butillustrative. Thus, the scope of the inventive concepts is to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing description.

What is claimed is:
 1. A magnetic memory device, comprising: a referencemagnetic structure and a free magnetic structure on a substrate; and atunnel barrier pattern between the reference magnetic structure and thefree magnetic structure, wherein the reference magnetic structurecomprises: a first pinned pattern; a second pinned pattern between thefirst pinned pattern and the tunnel barrier pattern; and an exchangecoupling pattern between the first pinned pattern and the second pinnedpattern, wherein the second pinned pattern comprises: a first magneticpattern adjacent the exchange coupling pattern; a second magneticpattern adjacent the tunnel barrier pattern; a third magnetic patternbetween the first magnetic pattern and the second magnetic pattern; afirst non-magnetic pattern between the first magnetic pattern and thethird magnetic pattern; and a second non-magnetic pattern between thesecond magnetic pattern and the third magnetic pattern, and wherein thefirst magnetic pattern has a hexagonal close-packed (HCP) crystalstructure or a face centered cubic (FCC) crystal structure, and a (0001)plane of the first magnetic pattern having the hexagonal close-packed(HCP) crystal structure, or a (111) plane of the first magnetic patternhaving the face centered cubic (FCC) crystal structure is parallel to atop surface of the substrate.
 2. The magnetic memory device of claim 1,wherein the second magnetic pattern has a body centered cubic (BCC)crystal structure, and a (001) plane of the second magnetic patternhaving the body centered cubic (BCC) crystal structure is parallel tothe top surface of the substrate.
 3. The magnetic memory device of claim1, wherein the second non-magnetic pattern has a same crystal structureas the second magnetic pattern.
 4. The magnetic memory device of claim1, wherein the third magnetic pattern includes a first surface and asecond surface opposite to each other, and wherein the first surface ofthe third magnetic pattern is in contact with the first non-magneticpattern, and the second surface of the third magnetic pattern is incontact with the second non-magnetic pattern.
 5. The magnetic memorydevice of claim 1, wherein the second magnetic pattern is in contactwith the tunnel barrier pattern, and the second magnetic patternexhibits a perpendicular magnetization property, which results frommagnetic anisotropy induced by a contact between the second magneticpattern and the tunnel barrier pattern.
 6. The magnetic memory device ofclaim 1, wherein the third magnetic pattern includes boron (B).
 7. Themagnetic memory device of claim 6, wherein the third magnetic patternincludes iron-boron (FeB).
 8. The magnetic memory device of claim 1,wherein the second magnetic pattern includes iron (Fe).
 9. A magneticmemory device, comprising: a reference magnetic structure and a freemagnetic structure on a substrate; and a tunnel barrier pattern betweenthe reference magnetic structure and the free magnetic structure,wherein the reference magnetic structure comprises: a first pinnedpattern; a second pinned pattern between the first pinned pattern andthe tunnel barrier pattern; and an exchange coupling pattern between thefirst pinned pattern and the second pinned pattern, wherein the secondpinned pattern comprises: a first magnetic pattern adjacent the exchangecoupling pattern; a second magnetic pattern adjacent the tunnel barrierpattern; a third magnetic pattern between the first magnetic pattern andthe second magnetic pattern; a first non-magnetic pattern between thefirst magnetic pattern and the third magnetic pattern; and a secondnon-magnetic pattern between the second magnetic pattern and the thirdmagnetic pattern, wherein the first non-magnetic pattern has a differentcrystal structure from the second non-magnetic pattern, and wherein amagnetization direction of the first magnetic pattern is parallel to amagnetization direction of the second magnetic pattern.
 10. The magneticmemory device of claim 9, wherein the magnetization direction of thefirst magnetic pattern is anti-parallel to a magnetization direction ofthe first pinned pattern.
 11. The magnetic memory device of claim 10,wherein the magnetization directions of the first magnetic pattern, thesecond magnetic pattern and the first pinned pattern are perpendicularto a top surface of the substrate.
 12. A magnetic memory device,comprising: a reference magnetic structure and a free magnetic structureon a substrate; and a tunnel barrier pattern between the referencemagnetic structure and the free magnetic structure, wherein thereference magnetic structure comprises: a first pinned pattern; a secondpinned pattern between the first pinned pattern and the tunnel barrierpattern; and an exchange coupling pattern between the first pinnedpattern and the second pinned pattern, wherein the second pinned patterncomprises: a first magnetic pattern adjacent the exchange couplingpattern; a second magnetic pattern adjacent the tunnel barrier pattern;a third magnetic pattern between the first magnetic pattern and thesecond magnetic pattern; a first non-magnetic pattern between the firstmagnetic pattern and the third magnetic pattern; and a secondnon-magnetic pattern between the second magnetic pattern and the thirdmagnetic pattern, and wherein the first non-magnetic pattern has ahexagonal close-packed (HCP) crystal structure or a face centered cubic(FCC) crystal structure.
 13. The magnetic memory device of claim 12,wherein a (0001) plane of the first non-magnetic pattern having thehexagonal close-packed (HCP) crystal structure or a (111) plane of thefirst non-magnetic pattern having the face centered cubic (FCC) crystalstructure is parallel to a top surface of the substrate.